Suspension Good or Bad Practice?

Post by **user_3150** » 21 Mar 2005, 22:26

Hello everyone. Our Xantia is only used every other week as my wife car shares to work. Is it a good idea to leave the suspension on it's lowest setting whilst it's stood or does it not make a blind bit of diffrence. Opinions on this much appreciated.

tonespeed1999 · Post by **tonespeed1999** » 21 Mar 2005, 22:56

leave it in its normal position,if if sinks,it sinks!!
wont hurt it!

406 V6 · Post by **406 V6** » 22 Mar 2005, 00:20

and by letting it sink, the escaping LHm will also lube the struts![:D]

Richard Gallagher · Post by **Richard Gallagher** » 23 Mar 2005, 02:09

Personally I always lower mine down as it only gets used every 2-4 weeks. I work on the theory that doing this reduces the pressures in the spheres so they may last longer and that it also 'exercises' the suspension struts.
What I have noticed is that on the Xantias I have bought that are fitted with anti-sink, is that compared with my 97 TD (which I have had from just a couple of weeks old and have always lowered) the rear on them is quite reluctant to lower right down onto their bump stops.
This continues for a few weeks until eventually the car 'settles down' quicker, due presumably to the struts and bearings being lubricated/exercised.
Whilst anti-sink may make Xantias more normal/user friendly I do think that there is a price to pay with it for long term longevity unless 'Citerobics' are performed regularly.

Post by **user_3150** » 25 Mar 2005, 14:50

Hi Richard, Thanks for the reply. I thought it might be good practice. I only saw your reply whilst doing a search on sagging rear suspension. It looks like I've got a sticking height corrector. Still I'm glad the clocks change this weekend maybe we won't have so many people getting cheesed of with our headlights shining in there back window.

ScottFromNZ · Post by **ScottFromNZ** » 25 Mar 2005, 20:01

It is interesting what you say, Richard, about lowering the car dropping the pressure in the spheres. I guess this would lower the leakage rate, but is there any negatives with having the car parked on the bump stops for days at a time?

ScottFromNZ · Post by **ScottFromNZ** » 25 Mar 2005, 20:05

Thinking about this a bit more, when I raise the BX it rides harder, I assume this is because the gas in the spheres is compressed to a higher pressure? But when spheres are down in pressure the ride seems to get firmer too at normal height......

adamskibx · Post by **adamskibx** » 10 Apr 2005, 07:32

I usually lower my BX down if im not using it for a while just for the novelty of it. I think a full sink then raise lubricates the struts a bit too. However when it comes to sphere life I would imagine that leaving the car high would be better even though the pressure increases. I dont know this for sure but id imagine most of the gas escapes through the rubber diaphram and not the metal and so by releasing the pressure on the other side of the sphere you make it easier for the gas to escape into the fluid area in the struts.
As for the ride getting poorer on the higher setting I would imagine it is because of the angle of the suspention components and the relative position of the top of the suspention travel. When the car is riding at the correct height the arms will be almost horizontal meaning that most force from bumps will be transfered directly into the struts. When its too high a significant component of that force will be transfered upwards through the non horizontal suspention arms. Also, if the car rides too high anyway it may well be the case that the sphere is pumped up a bit too much and will only allow a bit of travel. Of course, on maximum (service) height the pressures are pumped up dramatically in the sphere leaving the diaphram with nowhere to go and resulting in zero suspention travel.

FrenchLeave · Post by **FrenchLeave** » 11 Apr 2005, 01:16

Hi, ScottFromNZ, when you raise the suspension on your BX it doesn't increase the pressure in the spheres, it just pumps in more fluid at the same pressure. But yes, when the spheres are down in pressure the car will ride harder, this is because the gas in the spheres will be comressed more at the static load, so there will be less volume available to absorb the shocks. Interestingly, if the spheres are pressurised too high this will also give a firmer ride, for the same reason. Less volumetric change is needed to obtain the required bump load pressure.